The invention relates generally to surface protecting resilient bumpers, and more particularly to two-part resilient, surface protecting bumpers and methods therefor.
Resilient bumpers are known generally and used widely for protecting surfaces from scratching and skidding, for use as spacers and stand-offs, and for absorbing shock, and for dampening and isolating sound and vibration, among other uses. Resilient bumpers made from URETHANE and PVC materials available from ITW Fastex, Des Plaines, Ill., for example, come in a variety of shapes, sizes and colors with a self-adhering mounting surface on a matrix pad, which is pre-cut for easy removal and ready installation of the resilient bumpers on everything from cabinet doors and furnishings to printed circuit boards and electronic equipment, among other applications.
In one known process for manufacturing resilient bumpers, TEFLON coated die or mold plates having an array of recessed bumper cavities move end to end along a continuous conveyer. The die plates move first below a pre-fill station that dispenses a small quantity of a self-curing, liquified resilient material into the bumper cavities on the die plates to prevent the formation of air pockets therein during a subsequent filling operation. The liquified resilient material is supplied continuously to the bumper cavities from one or more relatively small diameter supply lines disposed a centimeter or so above the die plates and in alignment with each row of bumper cavities. After the pre-fill operation, the die plates move along the conveyor to a fill station where the bumper cavities and the recesses of the die plates are filled entirely with the liquified resilient material, which is thereafter leveled with a TEFLON coated scraper blade as the die plates move past the fill station. The die plates then move preferably past a heating station to accelerate the curing of the liquified resilient material. After curing, the die plates are separated from the resilient bumpers, which are interconnected by a continuous web of resilient material. An acrylic or other mounting adhesive and a removable cover strip are applied to the continuous web for some applications, and the resilient bumpers are pre-cut to permit separation thereof from the continuous web.
It is known generally to form the resilient bumpers from different materials to provide bumpers having different performance characteristics. In some applications, for example, it is desirable for the bumpers to slip or slide along the surface, whereas in other applications it is desirable for the bumpers to grip the surface to prevent sliding. Generally, resilient bumpers made from harder materials have reduced surface friction, and softer material bumpers have better surface friction. A bumper formed of a harder material for reduced surface friction, however, is not as effective, for example, for shock absorption or vibration isolation as is a bumper formed of a softer material. Similarly, a softer bumper that provides increased surface friction does not provide the same degree of firm support as does a harder bumper. Thus, in the past, there has been a trade-off between the performance characteristics of resilient bumpers based the hardness thereof, or more generally based on the material from which the bumper was formed. Yet, in many applications, it is desirable for resilient bumpers to have performance characteristics of both hard and soft materials, or more generally to have performance characteristics of more than one material.
The invention is drawn toward advancements in the art of resilient bumpers.
An object of the invention is to provide novel resilient bumpers and methods therefor that overcome problems in the art.
Another object of the invention is to provide novel resilient bumpers and methods therefor that are economical.
A further object of the invention is to provide novel resilient bumpers formed of at least two different resilient materials to provide resilient bumpers having performance characteristics of the two or more materials.
Another object of the invention is to provide novel resilient bumpers and methods therefor comprising generally a resilient body member having a surface engaging end portion with a surface contacting end, a fastening end portion with a fastening end, and a side portion with an axial dimension between the surface contacting end and the fastening end. The surface engaging end portion of the body member is formed of a first resilient material, and an axial portion of the resilient body member adjacent the surface engaging end portion thereof is formed of a second resilient material having a different performance characteristic than the first resilient material. The first and second resilient materials are bonded when the first and second liquified resilient materials are cured to a solid state.
Yet another object of the invention is to provide novel methods for making novel resilient bumpers comprising generally depositing a first liquified resilient material into a bumper cavity of a mold plate, depositing a second liquified resilient material into the bumper cavity on top of the first liquified resilient material, and curing the first and second liquified resilient materials to form a first resilient material bonded to a second resilient material, the first and second resilient materials having different performance characteristics.
Still another object of the invention is to provide novel methods for making novel resilient bumpers comprising generally depositing a first liquified resilient material into a bumper cavity of a mold plate, distributing the first liquified resilient material in the bumper cavity before depositing a second liquified resilient material into the bumper cavity on top of the first liquified resilient material, and curing the first and second liquified resilient materials to form a first resilient material bonded to a second resilient material, the first and second resilient materials having different performance characteristics.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.